mt7981-usb-sfp-patcher

Patch existing OpenWRT firmware (sysupgrade.itb) to use the USB3 on the MT7981 to connect to 2500Base-X SFP module.

Tested Device

CMCC RAX3000M

Tested OpenWRT Versions

23.05.4

How to use

Presquites

Install U-Boot Tools and Device Tree Compiler

Debian / Ubuntu: sudo apt install u-boot-tools device-tree-compiler

Arch Linux: sudo pacman -S uboot-tools dtc

Homebrew: brew install u-boot-tools dtc

Install python3 with hashlib, zlib

Steps

Clone this repository

git clone https://github.com/cyyself/mt7981-usb-sfp-patcher.git
cd mt7981-usb-sfp-patcher

Patch the firmware

wget https://downloads.openwrt.org/releases/23.05.4/targets/mediatek/filogic/openwrt-23.05.4-mediatek-filogic-cmcc_rax3000m-squashfs-sysupgrade.itb
python3 patch_itb.py openwrt-23.05.4-mediatek-filogic-cmcc_rax3000m-squashfs-sysupgrade.itb patched.itb

(Optional) Verify the patched dts

diff build/orig.dts build/patched.dts

8c8
<       model = "CMCC RAX3000M";
---
>       model = "CMCC RAX3000M with USB3SFP";
549,551c549,550
<                       phy-mode = "gmii";
<                       phy-handle = <0x1f>;
<                       phandle = <0x39>;
---
>                       phy-mode = "2500base-x";
>                       managed = "in-band-status";
686c685
<               phys = <0x21 0x03 0x0f 0x04>;
---
>               phys = <0x21 0x03>;
689a689
>               mediatek,u3p-dis-msk = <0x01>;
931c931
< };
---
> };
\ No newline at end of file

Use sysupgrade -F or LuCI to flash the patched firmware

It's normal to get a warning "Image check failed", but "Force upgrade" should work.

Limitation

Since there are only 2 Ethernet MACs in the MT7981 SoC, If your router uses both of them for WAN and LAN (e.g. CMCC RAX300M), the original eth1 (typically WAN port) will be disabled.

For OpenWRT Developers / Advanced Users

Please see this dts patch.

Notice

A patch to enable the flow control of the SFP module is under review.

imlk0/mt7981-usb-sfp-patcher